import 'dart:async';
main() {

    /*Future f1 = new Future(() {
      print("我是第一个");
    });
    f1.then((_) => print("f1 then"));
    print("我是main");*/

  Future<String> _testString() async {
    Future f = Future.delayed(Duration(milliseconds: 300), () {
      return "我是测试字符串===1";
    });
    String result = await f;
    print("我是测试字符串===2");
    return result;
  }

  _testAsyncKeyword() async {
    print("test函数开始了：${DateTime.now()}");
    print(await _testString());
    print("test函数结束了：${DateTime.now()}");
  }

  _testAsyncKeyword();


}
